Modern computing and display technologies have facilitated the development of systems for so-called “virtual reality” or “augmented reality” experiences, wherein digitally produced images or portions thereof are presented in a wearable device to a user in a manner wherein they seem to be, or may be perceived as, real. A virtual reality, or “VR,” scenario typically involves presentation of digital or virtual image information without transparency to other actual real-world visual input; an augmented reality, or “AR,” scenario typically involves presentation of digital or virtual image information as an augmentation to visualization of the actual world around the user.
The wearable device may include augmented and/or virtual reality glasses. The image can be displayed using image frames or raster scanned images. In a scanning image display system, each angle (or small angular range of the scan) of the light beams defines the pixels of the image. By scanning the mirrors in two orthogonal axes, a two-dimensional field of view (FOV) can be created. Scanned beams can be coupled through glasses lenses that take the form of waveguide displays. The image display systems can be mounted on each of the left and right sides of the glasses frames.
One drawback of scanned beam displays is that there is generally a tradeoff between scan frequency, which determines the product of resolution and frame rate on the one hand and, on the other hand, scan angular range which determines the angular field of view. Additionally, certain compact laser diodes that have a size suitable for incorporation in augmented reality glasses have a maximum modulation rate which again limits the product of resolution and frame rate.